This study explores the hypothesis that the development of delusions in depressed patients is due to the effects of increased hypothalamic-pituitary-adrenal (HPA) axis activity on central dopamine activity. Data on daily rhythms of cortisol, ACTH, and HVA - a dopamine metabolite - are collected for a baseline 24 hr. period in healthy controls, nonpsychotic depressed patients, and psychotic depressives. Relationships between these biological measures and those of depressive and cognitive symptoms and neuropsychological test results. Thereafter, all subjects receive o-CRH, hydrocortisone, or placebo under double-blind conditions. The acute and longer-range effects of these test substances on cortisol, ACTH, and HVA are explored over the next three days. Comparisons are made both within subjects and between groups. These studies will assist us in understanding how the HPA axis affects dopamine systems as well as clarify the relationships between glucocorticoid or dopamine measures and clinical symptoms, including neuropsychological test performance.